/*
 * Alloy Analyzer
 * Copyright (c) 2002 Massachusetts Institute of Technology
 *
 * The Alloy Analyzer is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * The Alloy Analyzer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with the Alloy Analyzer; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package alloy.transform;

import alloy.ast.ASTDepthFirstReplacer;
import alloy.ast.Node;

/**
 * Replaces one node by another.
 */

public class ReplaceNodeVisitor extends ASTDepthFirstReplacer {

    /** Node to replace */
    private Node _nodeToReplace;

    /** Node used to replace other node. */
    private Node _replacerNode;

    public ReplaceNodeVisitor(Node nodeToReplace_, Node replacerNode_) {
        _nodeToReplace = nodeToReplace_;
        _replacerNode = replacerNode_;
    }
    
    public Object visit(Node node_) {
        if (node_.equals(_nodeToReplace)) {
        	return (Node)_replacerNode.copy();
        } else {
            return super.visit(node_);
        }
    }
}
